Can the eames EA222 be used as a desk chair?  

Not unless you use a very LOW desk
... and like to recline while you work.
That chair has a much lower seat height (it's also not adjustable) and a significant pitch back. They make the soft pad executive version with a high back, perhaps that is what is confusing.

And...
The arms will bang into any standard-shaped desk that's low enough to be reached by someone sitting n the chair.

ok thanks. so why would...
ok thanks. so why would somebody want a lounge chair that looks like an office chair... this i do not understand.

In your own words, I am sure...
In your own words, I am sure that the people are just 'not bothered'.

Doesn't look like an office chair to me...
But of course I can understand why some might see it that way.
Mid-century modern furniture often has a lot in common with contract/industrial furniture: Absence of ornament, minimalist structure, "industrial" materials, etc.
Plus, Knoll and Herman Miller are the largest manufacturers of office furniture in the world. They have easy access to office-furniture buyers and -- until recently, anyway -- not very easy access to retail home-furniture buyers, so it makes much more sense for them to produce pieces that might be purchased for offices than to produce pieces that are suitable only for homes.

I think eames EA222 can be used as a desk chair. I do not remember properly but I have read somewhere about this Chair.